In the past, there have been proposed electromagnetic relays opening and closing contacts by use of magnetic force caused by electromagnets (see JP 2013-30308 A (hereinafter referred to as “document 1”)). The electromagnetic relay disclosed in document 1 includes an electromagnet, an armature to be rotated by magnetic force caused by the electromagnet, a movable contact to move in accordance with a rotation of the armature, and a fixed contact to be in contact or separate from the movable contact.
With regard to this electromagnetic relay, when a current flows through a coil of the electromagnet, the armature is rotated in a direction according to a flow direction of a current in the coil. The movable contact is movable between a position in which the movable contact is in contact with the fixed contact and a position in which the movable contact is separate from the fixed contact, in accordance with such a rotation of the armature.
In the electromagnetic relay disclosed in above document 1, when the movable contact moves away from the fixed contact, an arc may occur between the contacts. By lowering a level difference between a top part of the movable contact (part to be in contact with the fixed contact) and an attachment face of a contact holding member to which the movable contact is attached, the arc can more easily move from the movable contact to the contact holding member. This may be applied to a case of the fixed contact.
However, when the height of the movable contact is decreased in order to decrease the level difference between the top part of the movable contact and the attachment face of the contact holding member, the volume of the movable contact decreases, and therefore lifetime of contacts with regard to on and off operation is likely to be shortened, and the contacts are likely to adhered to each other by melting.